This invention relates generally to apparatus of the type used in combination with hand or power saws for accurately cutting rafter boards and the like at preselected angles. More particularly, the apparatus of the present invention relates to portable devices of the type having means for guiding the blade of a saw to enable the execution of precise rafter and other angle cuts.
It is frequently necessary, particularly in the building industry trade, to precut wooden members at various angles with a high degree of precision. For example, in preparing rafters for use in the construction of buildings, it is necessary to precut the rafter boards at precise angles depending upon the characteristics of the particular roof being constructed. In this regard, it will be recognized that pertinent characteristics which must be considered include such variables such as the rise and span of the roof and the like.
The industry has devised numerous devices to facilitate the angular cutting of wooden members such as rafter boards. The prior art devices typically include members for guiding the saw blade along the boards and indexing means for positioning the guide members relative to the boards at preselected angles in a horizontal plane. It is also known in the prior art to provide means whereby the device may be clamped to a work table for the convenience of the operator as well as means for allowing the guide to be adjusted in a vertical direction. Examples of prior art devices of the foregoing type may be found in U.S. Pat. No. 2,714,903, in the name of P. L. Miller, and entitled PORTABLE POWER SAW GUIDE AND SUPPORTING MEANS; U.S. Pat. No. 2,596,524, in the name of G. L. Bridwell, and entitled PORTABLE POWER SAW GUIDE AND SUPPORTING MEANS; U.S. Pat. No. 2,802,493, in the name of K. Horneland, and entitled GUIDE FOR PORTABLE POWER SAWS, and U.S. Pat. No. 2,589,554, in the name of J. P. Killian, and entitled SAW GUIDE FOR PORTABLE POWER-DRIVEN AND-OPERATED CIRCULAR SAWS.
While the prior art devices are generally acceptable in terms of accuracy, they are typically relatively large and expensive and therefore not altogether satisfactory from a practical viewpoint. In cutting rafters, for example, it would be highly desirable to appropriately cut each end of the board before removing it from its work supporting surface by utilizing a pair of saw guides each positioned at an opposite end of the rafter so that each piece of lumber would have to be handled only once. However, such a procedure is not presently practical due both to the size of available saw guides as well as the expense involved in purchasing duplicate devices. In addition, the relatively large size of prior art devices results in substantial inconvenience to the builder who must continuously handle the unit in an on the job situation.